Embryo does not seem to grow properly

Hello, I need your help.

At the moment I am on day 17, so tomorrow i hit the final phase.
But I am really worried.
Candling my eggs shows me that the embryo fills round about 1/3 of the egg.
The problem I have just with the Swedish flower hen eggs, not with the other eggs. The other eggs show me an embryo of the size that you would expect on day 17.

These are my own eggs, so there is no problem depending on shipping.

So, what to do?
I am thinking of starting the final phase, put them down, not on day 18 but one or two days later, because I am worried. I think they are far from ready to hatch. The size of the embryo makes me think the eggs are on day 14-15. I think when i would lay them down tomorrow, on day 18, the chicks - which are def alive - will die because they are still in the need of being turned.